Updated OpenSSL packages fix vulnerabilities

Updated OpenSSL packages that fix potential timing-based and modified
Bleichenbacher attacks are available for Red Hat Linux on IBM iSeries and
pSeries systems.

OpenSSL is a commercial-grade, full-featured, and open source toolkit that
implements Secure Sockets Layer (SSL v2/v3) and Transport Layer
Security (TLS v1) protocols as well as a full-strength general purpose
cryptography library.

In a paper, Brice Canvel, Alain Hiltgen, Serge Vaudenay, and Martin
Vuagnoux describe and demonstrate a timing-based attack on CBC ciphersuites
in SSL and TLS. An active attacker may be able to use timing observations
to distinguish between two different error cases: cipher padding errors and
MAC verification errors. Over multiple connections this can leak
sufficient information to make it possible to retrieve the plaintext of a
common, fixed block.

In order for an attack to be sucessful, an attacker must be able to act as
a man-in-the-middle to intercept and modify multiple connections, which all
involve a common fixed plaintext block (such as a password), and have good
network conditions that allow small changes in timing to be reliably
observed.

Researchers discovered a timing attack on RSA keys. Applications making
use of OpenSSL are generally vulnerable to such an attack, unless RSA
blinding has been turned on. OpenSSL does not use RSA blinding by default
and most applications do not enable RSA blinding.

A local or remote attacker could use this attack to obtain the server's
private key by determining factors using timing differences on (1) the
number of extra reductions during Montgomery reduction, and (2) the use of
different integer multiplication algorithms ("Karatsuba" and normal).

In order for an attack to be sucessful, an attacker must have good
network conditions allowing small changes in timing to be reliably
observed.

Additionally, the SSL and TLS components for OpenSSL allow remote attackers
to perform an unauthorized RSA private key operation via a modified
Bleichenbacher attack. This attack uses a large number of SSL or TLS
connections, using PKCS #1 v1.5 padding, and causes OpenSSL to leak
information regarding the relationship between ciphertext and the
associated plaintext, aka the "Klima-Pokorny-Rosa attack."

These erratum packages contain patches provided by the OpenSSL group that
enable RSA blinding by default and protect against the other vulnerabilities.

Because server applications are affected by these vulnerabilities, users
are advised to restart all services that use OpenSSL functionality, or
reboot their systems after installing these updates.

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

To update all RPMs for your particular architecture, run:

rpm -Fvh [filenames]

where [filenames] is a list of the RPMs you wish to upgrade. Only those
RPMs which are currently installed will be updated. Those RPMs which are
not installed but included in the list will not be updated. Note that you
can also use wildcards (*.rpm) if your current directory *only* contains
the desired RPMs.

Please note that this update is also available via Red Hat Network. Many
people find this an easier way to apply updates. To use Red Hat Network,
launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

86112 - New timing attack on OpenSSL applications

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0078
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0131
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0147
http://crypto.stanford.edu/~dabo/papers/ssl-timing.pdf
http://eprint.iacr.org/2003/052/

attack, Bleichenbacher, blinding, keys, OpenSSL, RSA